Three main reasons may lead to false alarms for burglar alarms

First, false alarm caused by improper design of the system The alarm of the burglar alarm is falsely alarmed. The equipment selection is the key to the system design. The alarm equipment has various types and each has its own characteristics, application scope and limitations. Improper selection can cause false alarms. . For example, the use of seismic detectors close to the source (airfield, railroad) can easily cause false alarms; the use of ultrasonic detectors in places where bats are frequent causes false alarms. This is because bats emit ultrasonic waves; High-frequency sounds such as ring tones and metal impact sounds can cause false alarms for single-technology glass break detectors. Therefore, to reduce false alarms caused by improper equipment selection, system designers must be familiar with the principles and characteristics of various alarm devices. Applicability and limitations. At the same time, we must also grasp the on-site environmental conditions, climate conditions, electromagnetic field strength, and changes in illuminance in order to select alarm equipment according to local conditions.

In addition to anti-theft alarm equipment and equipment selection, improper system design is also reflected in equipment and equipment installation location, installation angle, protective measures and system wiring and so on. For example, when a passive infrared intrusion detector is installed facing an air conditioner or ventilation fan, it will cause a false alarm of the system; if an active outdoor infrared detector is not used for proper sun protection (the sun shield is also best for protection), it is bound to Caused by the system of false alarms; alarm lines and power lines, lighting lines and other strong electrical circuit spacing is less than 1.5m, without the protection against electromagnetic interference, the system will also generate false alarms.

Second, improper construction caused by false alarm improper construction may also cause false alarm burglar alarm, mainly in the following areas: (1) did not strictly according to the design requirements of construction. (2) Improperly installed equipment or improper inclination. (3) Solder joints have vacant welds, burrs, or shielding measures. (4) The sensitivity of the device is poorly adjusted. (5) Inspection equipment for construction does not meet the measurement requirements. The solution to the above problems is to strengthen the supervision and management of the construction process and implement the safety supervision system as soon as possible. This will help improve the quality of the project and reduce the number of false alarms due to construction.

Third, the environmental alarm caused by false alarms due to environmental noise caused by false alarm refers to the alarm system in the normal state of operation, from the principle of unavoidable, and the fact is not needed, is false alarm. For example, thermal airflow causes false alarms from passive infrared intrusion detectors; high-frequency sounds cause false alarms from single-technology glass break detectors; and ultrasonic sources cause false alarms from ultrasonic detectors. The most effective measure to reduce such false alarms is to use dual detectors (two different detectors detect the “target” at the same time, and the alarm only sends an alarm signal). The current products include: microwave-passive infrared double detector, voice-activated glass broken double detector, ultrasonic-passive infrared double detector and so on. However, some environmental noise detectors are powerless. For example, rats are in the protection zone; pets move around indoors. To this end, scientific and technical personnel have introduced micro-processing technology into the alarm system so that they have a certain ability to identify and think, and can judge to some extent whether it is an intruder or an alarm caused by environmental noise.